Synthetic bulk fabric treated with organically modified sio&#39; 2 &#39;aquasol

ABSTRACT

A synthetic fabric bulk pile carpet and like soft material having both improved antistatic and antisoil characteristics obtained by applying from about 0.5 to 4% SiO2 based upon the dry weight of the pile of an organically modified silica aquasol wherein generally there exists a double layer of an organic quaternary salt or hydroxide on each silica particle. Preferred quaternaries are dicoco dimethyl ammonium chloride, di(hydrogenated tallow)dimethyl ammonium chloride, tallow trimethyl ammonium chloride, and lauryl trimethyl ammonium chloride and methods of treating carpets and fabrics are disclosed.

United States Patent [191 Payne et al.

[451 Oct. 14, 1975 SYNTHETIC BULK FABRIC TREATED WITH ORGANICALLYMODIFIED SiO AQUASOL [75] Inventors: Charles C. Payne, Chicago; RichardE. Bloemke, River Grove; David P. Schaefer, l-linsdale, all of 111.

[73] Assignee: Nalco Chemical Company, Oak

Brook, 111.

[22] Filed: Oct. 31, 1973 [21] Appl. No.: 411,582

[52] US. Cl. 428/96; 427/427; 428/241;

428/331 [51] Int. Cl. B32B 3/02; B32B 5/16; 3328 33/00 [58] Field ofSearch 1l7/139.5 CF, 138.8 N,

[56] References Cited UNITED STATES PATENTS 2/1956 Rainard et al. 117/1395 CF 2/1956 Florio et al. 117/139.5 CF

2,877,142 3/1956 Rusher et a1 117/169 R 2,928,754 3/1960 Schappelll7/139.5 CF 2,999,774 9/1961 Schappel 117/139.5 CF

Primary ExaminerRalph Husack Assistant ExaminerSadie L. Childs Attorney,Agent, or FirmJohn G. Premo; John S. Roberts [5 7 ABSTRACT 5 Claims, 1Drawing Figure PRODUCT A AS AN ANTISTAT HALF LlFE TIME, SECONDS .h

NYLON CLOTH v SiO SOLUTION USED PRODUCT A AS AN ANTISTAT NYLON CLOTHHALF LIFE TIME, SECONDS I I L0 2.0 3.0 4.0 5.0 6.0 7.0

%'SIO SOLUTION USED SYNTHETIC BULK FABRIC TREATED WITH ORGANICALLYMODIFIED SIO AQUASOL The present invention is concerned with theutilization of a modified aquasol on pile fabric of carpets and It ispreferred that the starting aqueous silica sols used in this procedurebe double deionized by any of the well-known techniques. If the sol isnot double deionized, it will benecessary to dilute the starting aque-Na O, percent ous silica sol to a roximatel 35% silica. on other softmaterial and this application contains sub- 5 pp y ject matter relatedto Peter H. Vossos, Ser. No. A preferred starting silica sol forpurposes of the 373,217, filed June 25, 1973. The modified aquasol ispresent invention is that denoted as Nalcoag 1034A, a coated with adouble layer of a quaternary ammonium double deionized sol, containing34% colloidal silica TABLE I Nalcoag 1030 1034A I035v 1050 1060 11301140 Percent colloidal silica, as Si0 30 34 35 l 50 50 30 40 r 10.2 3.18.6 9.0 8.5 10 Average particle'size, millimicrons I 1 1-16 16-22 16-2217-25 40-60 8 Average surface area, M lgram 190-270 135-190 135-190120-176 50-75 375 200 Specificgravity at 68F 1.205 1.230 1.255 1.3851.390 1.214 L296 Viscosity at 77F,c.p.s. 5* 5* 5 70* 5-10 7 8 0.40 006*0.10 0.30 0.10 0.65 0.40

Less than salt or hydroxide. The pertinent prior patent art is notedbelow and deals with related compounds and methods of treating textileswherein the treating agent is an organosol modified with a quaternaryammonium compound: i

US. Pat. No

US. Pat.No US. Pat. No

' Uf SfPat. No."3, 033,699 Aarons et al. (duPont) is.

specially of ihte restwith' respect to pile fabric and carpets bytreatment with combination of silica andclay which fun'ctions 'asacombined antistatic and antisoil treatment. i i p L In the literature E.Matijevic, Surface and Colloid Scie r'lce, Volume 6, John Wiley andSons, 1973, pages 74, 84-86, teaches the effect of adding organic basesto aqueous silica sol and'the resultant antisoil and antistatic' orconductive properties added there to.

Additionally, R. K. Iler, The Colloid Chemistry of Silicd'dnd silicates,Cornell Press, 1955 pages 100-1 12, relates to the types and effectsofcounter-ion concentration of additives to reverse the charge on thesilica.

1n the present descriptionthe terrri fsoft materials" embraces fabricsconsisting of carpets, wall coverings, dr'aperies,car interiors, etc.

'THESTARTING AQUEOUS SILICA SOLS Generally, any aqueous silica sol canbe used for this invention These arewell known to the art. The startingaqueous silica' sol carfrangeffrom 10 to 60 percent by weight ofdiscrete, dense colloidal particles of amorphous silica; The averageparticle diameter can range from 3 to 150 millimicrons and can have anaverage surface area from 20 M /g. to 1,000 M /g. It is preferred thatthe starting aqueous silica sol be from 30 to percent by weight ofdiscrete, dense colloidal particles of amorphous silica. The preferredparticle diameter should range from 16 to 22 millimicrons and have anaverage surface areafrom l35 to 190 M /g,

The following is, atable of commercially available calculated as SiOTypically Nalcoag 1034A contains less than 600 ppm of sodium, Na,calculated i as Na O, and ppm of chloride, Cl, as combined chloride andsulfate.

In utilizing commercial silica sols, effort was made to start with arelative concentration of SiO :Na O of greater than about 200/1.

THE QUATERNARY AMMONIUM COATING .The quaternary ammonium compound hasthe formula:

wherein R R are methyl R is methyl or a C,,-C long hydrocarbon chain; Ris a C,;--C long hydrocarbon chain; Xis an anion selected from the groupconsisting of chloride, bromide, iodide, and hydroxide. Anotherquaternary ammonium compou nd that has In the formulae above thenitrogen substituent groups are chosen with the viewpoint of providingwater solubility or having some degree of water dispersibility providedby 2 or 3 methyl coupled with 1 or 2 long hydrocarbon chain groups toprovide the necessaryfat'ty residue for the coating. Thus, operablecompounds are those where R, or R R, are lauryl, plamityl, stearyl,oleyl, octyl, caprylyl, etc., and these may be similar or dissimilar.Preferred substituents for R and R are quaternary amines derived frommixtures of fatty acids that occur in various fats and oils such ascoconut oil, hydrogenated tallow, hydrogenated castor oil, etc. Specificexamples of preferred quaternary compounds include:

Lauryl trimethyl ammonium chloride Dicocodimethyl ammonium chloride.Di(hydr'ogenated tallow) dimethyl ammonium chloride Tallow trimethylammonium chloride An additional operable compound not consonant with theformulae supra, is tricaprylmethyl ammonium chloride. Additionallyoperable are the alkyl trimethyl amthe outward'nitrogen, which is partof the second coating of quaternary. 7

SOLVENT The starting silica aquasols are preferably double deionizedsols, and it has been found highly advantageous to add a hydrophilicbridging solvent such as a lower alkanol and a preferred alkanol isisopropanol. The

amount of isopropanol utilized is preferably about 3 l% by weight of thewater in the aquasol. The lower alkanol, e.g., isopropanol, convenientlyis added during the preparation of the aquasol at the point of additionof the quaternary. The addition of the alkanol helps stabilize thequaternary and to lessen gelation and precipitation tendencies.Generally, the mixture is stirred from about 1-60 minutes.

METHOD OF MANUFACTURE.

particle, Asthe first layer goes on, it neutralizes any charge(negative) on the silica particle and imparts an organophilic surface.At this point, the sol becomes less stable and there is a tendency forgelation or precipitation to occur. There is a decided thickeningvisually noticeable. The lower alkanol solvent which is a requisite actsto solubilize or disperse the coated sol in water. As the second coatbecomes a layer, a different charge (positive) is imparted to theparticle and the sol is restabilized. The second layer is oriented withits organophilic portion toward the surface and its ionic portion towardthe solvent.

A preferred manufacturing process which enables the manufacture ofthepresent double coated layer is as follows. In step one, the loweralkanol solvent is added to the quaternary amine in excess; As step two,

the colloidal silica is added with sustained mixing into 7 deionizedsolwiththe properties like Nalco 1034A (see Table l). A silica sol of thistype has little charge on its surface and tends to be more stable in thecritical period during the application of the firist coating or in theintermediate stage of manufacture. Alternative commercial sols may, beused, but optimum results are obtained by utilization of sols having-190 M /gram average surface area. In the initial contact between thesilica particle and the amine, the system may thicken, but the alcoholprevents gelation or precipitation until the system thins out whenadditional silica sol is added.

By the procedure of adding the sol to the amine solution, there isalways an excess of amine and the two layers can go onto the silicasequentially. Further the simultaneous existence of both positive andnegative sols is avoided.

The above is the preferred method for production of the'double layeredsols. Other less preferred methods are by utilization of high shearmixing and in certain favored cases the elimination of the alcoholstabilizer.

THE AMOUNT OF QUATERNARY COATING ON SiO r The amount of the quaternaryin'jrelation to the silica depends uponthe particle size of thecolloidal silica.

The smaller the particle size, the more quaternary will I be required.In general, the ratio of SiO; to quaternary will be from 25 to l to 2 tol, and more often will be from 3:1 to 10:]. For an average particlediameter of 20 millimicrons a ratio of about} to l is typical.

The above percentage or concentration additions of quaternary have beenfound optimum in using the combination of Nalcoag 1034A and thequaternary dicoco dimethyl, ammonium chloride. However, additionalvariations over the range depending especially on the quaternaryselectedarenecessary as the length of the long carbon chain or chains varies.The size of the silica particle also affects the amount of quaternarynecessary. The purpose of the present invention is to produce amolecular double layer of quaternary and generally reversal of charge. vl

The present formulation uniformly requires a layer of quaternary whichis physically sorbed and contains a molecular double layer. In the caseof a charged silica sol, layer one, the innermost layeraround thesilica,

of the quaternary silica compounds of the present in- I vention to pilefabric and carpets is usually in the nature of 14% by added weight basedupon the percent of silica as Si0 added to the dry weight of the pile.Less than about 1% or in some cases, 0.5% gives lack of treating effectandabove 4% produces a white carpet or pile fabric.

in the past'it has been found that commercial quaternary compounds usedas antistatic agents present a 1 very bad soiling problem and'in factare prosoil agents. 1 However, in the present compounds, when'combinedwith silica, these carpet-treating preparations can be viewed as bothantistatic and antisoil. The amount of coating or treating agent issimilar to the prior art, for example, US. Pat. No. 2,622,307 Cogovan(Mohawk) at column 4, lines 33-49, when referring to the coating ofcolloidal silica on pile yarns. The combination of antistatic andsoil-resistant components is also noted in the prior art in US. Pat. No.3,033,699 Aarons et al. (duPont) which utilizes a combination of clayand colloidal silica sol and in that patent also is utilized the soiltesting using Sanders and Lamberts synthetic soil at Example 1 andcolumn 4.

FIG. 1 represents results from antistat tests at different percentagesof silica where the half-life time expressed in seconds was measuredaccording to the procedure of Example III-A.

In the followinng experimental procedures the antistatic effect is dueto the quaternary component and is measured and observed on fabricsamples treated by dip methods. The antisoil effect is due to the silicacomponent and is measured on fabric samples treated by spraying.

EXAMPLE I Preparation of Quaternary Coated Silica Aquasols A 34% SiO solin H O was coated with a fatty quaternary amine. To 11.2 parts of Arquad2C-75 (dicoco dimethyl ammonium chloride) was added 3.5 parts ofisopropanol followed by 85.3 parts of Nalcoag 1034A deionized silicasol. The preparation was repeated several times and it was noted thatthe results improved where slow addition was followed with good mixingin the preparation to avoid the formation of gel particles. It wasfurther noted that the product went through a very thick stage as the1034A silica sol was added, but the sol thinned out when it was alladded. The product was found to be stable over a one-year period.

An additional run which doubled the amount of isopropanol wasadvantageous in thespeed of solubility of the quaternary. The silica solutilized, Nalcoag 1034A, has a pH of 3.4. In separate runs, this pH wasvaried from 3.4 to 3.8 without adversely affecting the product. However,where the pH was lowered to about 2.9, difficulties were experiencedwith a cloudy product which did not exhibit a sol-like appearance.

Additional experiments or runs were made with Na]- coag 1050, a 50%colloidal SiO which had been diluted to about 35% and the results werequite similar to those obtained utilizing the 34% SiO or Nalcoag 1034Aabove as shown in Example 11.

EXAMPLE 11 Preparation of Double Coated Silica Sol To 33.6 grams ofArquad 2C-75 was added 10.5 grams isopropanol followed by 150 ml ofNalcoag 1050 silica sol diluted with 90 grams of water. The preparationwas made with good mixing throughout the addition steps. The productbecame very thick during the Nalcoag 1050 addition but'thinned out againafter a period of a few minutes. The product is stable over a one-yearperiod.

EXAMPLE IIIA Antistatic Properties 1 Static electricity tests were doneon pieces of nylon cloth pre-prepared by washing with detergent for 1cycle and then washing without detergent for 1 cycle before drying. Thenylon cloth was then cut into 5 inches X 5 inches squares and immersedin the test solution, wrung out to wet retention, thus giving acarry-over of 2.15% silica based on dry weight of the cloth, and driedat C for 5 minutes. Statis electricity tests were performed using theStati'Tester, Model 169, from Most Associates, Inc., Marblehead,Massachusetts. A voltage of from 50-300 volts at 100 milliamps wasapplied to the nylon cloth. The initial voltage was measured and thenthe current shut ,off.The time required for the voltage to drop to halfits initial value with no current applied was recorded as the half-lifetime. The shorter the time, the faster the charge dissipated from thecloth.

In the above, the quaternary utilized was dicoco dimethyl ammoniumchloride and the original silica sol was 1034-A.

Results of the tests are shown below.

Treating Solution Initial Voltage Half-Life Time Water 215 10' min.

0.87% Quilt-2.15% 197 1.5 sec.

Silica Sol 215% Silica Sol 200 10 min.

The results show that the quaternary modified silica sol functions as aneffective antistatic agent and that the silica sol alone does not.

EXAMPLE III-B Additional experiments were made utilizing the procedureof Example III-A but substituting di(hydrogenated tallow)dimethylammonium chloride, tallow trimethyl ammonium chloride, or lauryltrimethyl ammonium chloride for the dicoco dimethyl ammonium chlorideutilized in Example III-A.

EXAMPLE III-C Utilizing the procedure of Example III-A, additional testswere made with different silica sols at a 1% solid silica level. TableII shows the results of the tests.

Prepared by producing an organic double coating on a silica solv 1034A.which double coating is dimethyl dicoco ammonium chloride. in such amanner that the product contains 30% SiO, and 8% quaternary. i

TABLE III Comparison of Product A vs Other Commercial AntistatFormulations Initial Half Life 26C emp Sample Dilution Voltage Time RH8% Control 205 10 min. 1 (Chicago Tap Water) ProductA 1:8 1 sec. Statico1:4 210 1 sec. Bonds EI-IP 1:26 80 0.5 sec.

TABLE Ill-Continued Sample Dilution Time RH 8% Voltage *Staticomanufactured by Walter Leggc Company. Chicago. "Bonds E1-1P26-12manufactured by Bond Chemical Products. Chicago. Both of the abovecompounds are fatty quaternary compounds.

EXAMPLE III-D Utilizing the test procedures of Examples Ill-A, B, and C,certain antistatic properties were ascertained as follows. Thecomponents of Product A were checked individually for their antisoilingcharacteristics. This was done at several concentration levelscorresponding to the following dilution ratios of the product:

1. 1:8 dilution of Product A 2. 1:15 dilution of Product A A 1:8dilution of Product A contains 3.9% silica and 1:6% quaternary (dicocodimethyl ammonium chloride). A 1:15 dilution of Product A contains 2.5%silica and 0.87% quaternary. Tests were run on the individual componentsof each dilution for antistat values and the results are reported belowin Table IV.

ammonium chloride The results show that the silica needs the quaternarydouble coating to give antistat properties to the product.

EXAMPLE IV-A Antisoil Properties Testing of Product A for antisoilingproperties required formulating a synthetic dirt which would soilcarpeting evenly. Following the recommendation of US. Pat. No. 3,033,699Aarons et al. (duPont), a bulked Sanders & Lambert synthetic dirt wasprepared. This dirt mixture is the standard dirt mixture used forantisoiling tests by industry and gives fairly reproducible results witheven soilings.

90% nylon-10% wool carpet samples were sprayed with test solutions togive a coverage of about 2% silica based on the weight of the pile ofthe rug. After drying, the test samples were placed along the wall of aquart metal can. About 800% inch steel balls and 2.0g synthetic dirtwere added to the can. The can was rotated on a set of rollers for 1%hour at 120 rpm. The carpet samples were then vacuumed and thebrightness measured on a brightness meter made by Martin Sweets Co.,Louisville, Ky.

The quaternary dicoco dimethyl ammonium chloride and the original silicasol was 1034-A.

Results of the tests are shown below.

Brightness Brightness After Soil- 7r of Treating Before ing and OriginalSolution Soiling Vacuuming Brightness Water 24.4 15.0 61.5 0.8% Quat-24.4 16.4 67.2 2.15% Silica Sol 0.87% Quat 24.4 12.7 52.0

v The results show that the quaternary modified silica sol functions asan effective antisoilant and that the quaternary alone actually behavesas a prosoilant.

EXAMPLE IV-B Additional experiments were made utilizing the procedure ofExample IV-A but substituting di(hydrogenated tallow) dimethyl ammoniumchloride, tallow trimethyl ammonium chloride, or lauryl trimethylammonium chloride for the dicoco dimethyl ammonium chloride utilized inExample IV-A.

EXAMPLE rv-c Soiling characteristics of textile pile treated withProduct A versus some selected commercial products are shown below inTable V.

TABLE v Soiling Tests of Product A Versus Selected'Commercial Productsof Original Sample Dilution Brightness Brightness Original 24.9 100.0Untreated 8L 14.2 57.0 Soiled Product A 1:8 15.0 60.2 Statico 1:4 1 1.947.8 Bonds EHP26-12* 1:26 10.5 42.2

*Statico manufactured by Walter Legge Co., Chicago. *Bonds El-1P2612manufactured by Bond Chemical Products. Chicago. Both of the abovecompounds are fatty quaternary compounds.

EXAMPLE V Static and soiling characteristics of fabric treated with acomposition similar to Product A except that the silica sol was analkaline sol, Nalcoag 1050, rather than Nalcoag 1034A. Results are shownbelow.

TABLE VI 1 Antistat Values for Quat-IOSO Products Versus Product A Theaqueous silica sol sold by Nalco Chemical Co., Chicago, under the nameNalcoag 1050. 5

TABLE V11 Antisoil Values for Quart-1050 Product Versus Product A 7: ofOriginal Sample Dilution Brightness Brightness Original J 20.5 100.0Untreated 13.1 63.9 & Soiled Product A 1:8 16.8 82.0 Quat-l050 1:8 17.384.4 Product A 1:15 16.1 78.5

The results indicate that the Quat-lOSO product from alkaline stabilizedvalues gave both antistat and antisoil values comparable with the acidstabilized sol of Product A.

We claim:

1. Synthetic bulk fabric having improved antistatic and antisoilproperties, said fabric having been treated with an aquasol containing aminor amount of an aqueous polar solvent selected from lower alkanolshaving uniformly dispersed therein discrete dense colloidal particles ofamorphous silica having an average particle diameter of 3150millimicrons and average surface area of from about M /g to 1000 M /g,said silica particles having absorbed on their surfaces a quaternaryammonium salt or hydroxide, with the weight ratio silica, expressed asSiO to the quaternary ammonium being at least 2:1 wherein the quaternaryammonium has the formula:

wherein R R are methyl;

R is methyl or a C -C long hydrocarbon chain;

R is a C C long hydrocarbon chain;

X is an anion selected from the group consisting of chloride, bromide,iodide, and hydroxide.

2. The synthetic bulk pile carpet fabric according to claim 1 whereinthe quaternary ammonium salt or hydroxide is dicoco dimethyl ammoniumchloride.

3. The synthetic bulk pile carpet fabric according to claim 1 whereinthe quaternary ammonium salt or hydroxide is di(hydrogenatedtallow)dimethyl ammonium chloride.

4. The synthetic bulk pile carpet fabric according to claim 1 whereinthe quaternary ammonium salt or hydroxide is tallow trimethyl ammoniumchloride.

5. The synthetic bulk pile carpet fabric according to claim 1 whereinthe quaternary ammonium salt or hydroxide is lauryl trimethyl ammoniumchloride.

1. SYNTHETIC BULK FABRIC HAVING IMPROVED ANTISTATIC AND ANTISOILPROPERTIES, SAID FABRIC HAVING BEEN TREATED WITH AN AQUASOL CONTAINING AMINOR AMOUNT OF AN AQUEOUS POLAR SOLVENT SELECTED FROM LOWER ALKANOLSHAVING UNIFORMYL DISPERSED THEREIN DISCRETE DENSE COLLOIDAL PARTICLES OFAMORPHOUS SILICA HAVING AN AVERAGE PARTICLE DIAMETER OF 3-150MILLIMICRONS AND AVERAGE SURFACE OF FROM ABOUT 20M2/G TO 1000M2/G SAIDSILICA PARTICLES HAVING ABSORBED ON THEIR SURFACES A QUATERNARY AMMONIUMSALT OR HYDROXIDE, WITH THE WEIGHT RATIO SILICA, EXPRESSED AS SIO2, TOTHE QUATERNARY AMMONIUM BEING AT LEAST 2:1 WHEREIN TE QUATERNARYAMMONIUM HAS THE FORMULA:
 2. The synthetic bulk pile carpet fabricaccording to claim 1 whereiN the quaternary ammonium salt or hydroxideis dicoco dimethyl ammonium chloride.
 3. The synthetic bulk pile carpetfabric according to claim 1 wherein the quaternary ammonium salt orhydroxide is di(hydrogenated tallow)dimethyl ammonium chloride.
 4. Thesynthetic bulk pile carpet fabric according to claim 1 wherein thequaternary ammonium salt or hydroxide is tallow trimethyl ammoniumchloride.
 5. The synthetic bulk pile carpet fabric according to claim 1wherein the quaternary ammonium salt or hydroxide is lauryl trimethylammonium chloride.